Intermittent power plants use intermittent energy resources to generate electrical power using, for example, solar photovoltaic modules or wind turbines. However, variations in solar irradiation or wind speed cause variations in the power generated by intermittent power plants. This is referred to as energy variability. Energy variability may lead to variations in the voltage or frequency of electricity delivered to electricity consumption devices. A group of power plants, electricity consumption devices, and associated infrastructure spread over a geographical area may form an electric power grid or utility grid. Variations in power generated by intermittent power plants can cause variations in operating conditions in utility grids, including voltage and frequency, beyond their standard or desired ranges.
As mentioned above, a utility grid typically includes a plurality of power plants which are spread over a geographic area. The utility grid also typically includes electricity consumption devices as well as grid infrastructure, such as infrastructure for interconnection, control, maintenance, and/or improvement of the power plants, the electricity consumption devices, and/or any additional infrastructure. For example, the utility grid may include electrical distribution lines interconnecting the power plants, electricity consumption devices, and other devices within the utility grid.
Typically, operating conditions in the utility grid are managed by an energy management system. The utility grid's energy management system controls power plants that use continuous energy resources like coal, natural gas, oil or hydro as well as conventional control devices such as transformers, circuit breakers, capacitors, and reactors to keep the operating conditions within a desired range. The electricity parameters controlled by the energy management system, hereinafter referred to as operating conditions, may include active and reactive power, power factor, voltage, and frequency.
One problem with existing utility grids is that as the capacity of intermittent power plants in these grids grows, the ability of energy management systems to maintain operating conditions in these grids within desired ranges by adjusting the power generation of power plants that use continuous energy resources and/or by configuration of conventional control devices becomes limited. In turn, this limits the ability of the utility grid to accept economically and environmentally valuable power from intermittent power plants while maintaining grid stability and may result in additional wear on utility infrastructure and control devices such as distribution transformers. In particular, conventional control systems do not include adequate provisions aimed at managing operating conditions in utility grids that include intermittent power plants.
A need therefore exists for an improved utility grid, intermittent energy management system, and method for managing operating conditions in a utility grid. Accordingly, a solution that addresses, at least in part, the above and other shortcomings is desired.